This invention relates to a convertible two cycle/four cycle engine that has an electronically operated gas disbursement system for instantaneous conversion and variable control. The electronically operated gas disbursement system enables optimized performance of the engine in either the two stroke cycle or the four stroke cycle.
For ordinary driving conditions, a typical vehicle is powered by an engine that is sized for the maximum performance requirement of the vehicle. For example, a passenger vehicle passing another vehicle on a hill may for a brief period utilize the maximum power of the engine. At virtually all other times, from low speed city driving to highway cruising the power demand is a fraction of the available power. Over-dimensioned engines with large displacements are therefore constructed to meet only occasional power demands.
The situation for large displacement working vehicles is even more dramatic. Freight hauling tractor-trailers, delivery trucks and other road vehicles are designed with engines to accommodate full loads. When traveling empty, the power requirement is substantially diminished. Similarly, marine engines often must shift from high speed or power operation to low speed where the engine operates in idle for long periods of time. Unused displacement or over displacement results in over-sized, large engines with a multiplicity of cylinders, having a weight and complexity resulting in an unnecessary consumption of fuel and excess pollution.
Existing internal combustion engines are usually limited in their operation to two or four stroke cycles. The engines have a fixed mechanical gas distribution system, with set angular phases for intake and exhaust, which are optimized for a limited range of operation. With fixed compression ratios and limited means of optimizing performance for all ranges of power, torque and engine speed, fuel consumption is typically characterized by the "hook shape" specific fuel consumption curve with one point of minimum fuel consumption. Adaptation for the three ranges of operation, city power, cruise power, and acceleration power become a compromise with no one engine optimized for all conditions.
Although certain improvements to engine design have addressed these problems, for example, the use of a turbocharger for high performance operation, satisfaction of power demand is at the expense of optimized fuel consumption.
The engine of this invention resolves the problems of a universal engine optimized for all operating conditions by combining the power range achievable by a combined two cycle/four cycle engine with that of a two cycle engine. The convertible two cycle/four cycle engine of this invention is provided with an infinitely variable motive gas distribution system that is freed from cam controlled, mechanical actuation systems. The integrated engine system utilizes a fast acting, electro-hydraulic actuator for optimization of the intake and exhaust cycle in both the two cycle and four cycle mode of operation.